Receiver with flexible link synchronization

Abstract

A receiver includes: a PHY layer, and a processor coupled to the PHY layer. The processor is configured to: receive a set of data bits from the PHY layer; compare the set of data bits to a sync header pattern; determine a mismatch metric responsive to the comparison and to an adjustable scaling factor, and execute link synchronization operations based on the mismatch metric.

What is claimed is: 
     
       1. A receiver comprising:
 a PHY layer; and 
 a processor coupled to the PHY layer and configured to:
 receive a set of data bits from the PHY layer; 
 compare the set of data bits to a sync header pattern, wherein the comparing includes comparing each bit of the set of data bits to a respective bit of the sync header pattern to detect a corresponding bit mismatch; 
 determine a mismatch metric based on the corresponding bit mismatches and an adjustable scaling factor; and 
 execute link synchronization operations based on the mismatch metric. 
 
 
     
     
       2. The receiver of  claim 1 , wherein the processor is configured to execute the link synchronization operations by:
 comparing the mismatch metric to a mismatch threshold; 
 incrementing a sync index offset responsive to the mismatch metric being greater than the mismatch threshold; and 
 repeating the receive, determine, comparing, and incrementing for new sets of data bits based on the sync index offset until a related mismatch metric is less than the mismatch threshold. 
 
     
     
       3. The receiver of  claim 1 , wherein the mismatch metric is a first mismatch metric, and the processor is configured to execute the link synchronization operations by:
 repeating the receive, and determine for X sets of data bits offset by an offset, where X is an integer greater than 1; 
 determining a cumulative mismatch metric based on the first mismatch metric and each mismatch metric determined for the X sets of data bits; 
 comparing the cumulative mismatch metric to a threshold; and 
 completing link synchronization responsive to the cumulative mismatch metric being less than the threshold. 
 
     
     
       4. The receiver of  claim 3 , wherein the processor is configured to execute the link synchronization operations by:
 incrementing a sync index offset responsive to the cumulative mismatch metric being greater than the threshold; 
 repeating the receive, and determine for Y new sets of data bits offset by an offset, where Y is an integer greater than 2; 
 determining a new cumulative mismatch metric based on each mismatch metric determined for the Y sets of data bits; 
 comparing the new cumulative mismatch metric to the threshold; and 
 completing link synchronization responsive to the new cumulative mismatch metric being less than the threshold. 
 
     
     
       5. The receiver of  claim 3 , further comprising a link layer configured to decode Reed-Solomon Forward Error Correction (RS-FEC) encoded data based on the completed link synchronization. 
     
     
       6. The receiver of  claim 1 , wherein the processor is configured to:
 perform link synchronization based on the adjustable scaling factor having a first value and mismatch metrics for a first number of sets of data bits; and 
 perform link maintenance based on the adjustable scaling factor having a second value and mismatch metrics for a second number of sets of data bits, the second value greater than the first value, and the second number of sets greater than the first number of sets. 
 
     
     
       7. A method comprising:
 receiving a set of data bits; 
 compare the set of data bits to a sync header pattern, wherein the comparing includes comparing each bit of the set of data bits to a respective bit of the sync header pattern to detect a corresponding bit mismatch; 
 determine a mismatch metric based on the corresponding bit mismatches and an adjustable scaling factor; and 
 execute link synchronization operations based on the mismatch metric. 
 
     
     
       8. The method of  claim 7 , wherein executing the link synchronization operations includes:
 comparing the mismatch metric to a mismatch threshold; 
 incrementing a sync index offset responsive to the mismatch metric being greater than the mismatch threshold; and 
 repeating the receive, determine, comparing, and incrementing for new sets of data bits based on the sync index offset until a related mismatch metric is less than the mismatch threshold. 
 
     
     
       9. The method of  claim 7 , wherein the mismatch metric is a first mismatch metric, and executing the link synchronization operations includes:
 repeating the receive, and determine for X sets of data bits offset by an offset, where X is an integer greater than 1; 
 determining a cumulative mismatch metric based on the first mismatch metric and each mismatch metric determined for the X sets of data bits; 
 comparing the cumulative mismatch metric to a threshold; and 
 completing link synchronization responsive to the cumulative mismatch metric being less than the threshold. 
 
     
     
       10. The method of  claim 9 , wherein executing the link synchronization operations includes:
 incrementing a sync index offset responsive to the cumulative mismatch metric being greater than the threshold; 
 repeating the receive, and determine for Y new sets of data bits offset by an offset, where Y is an integer greater than 2; 
 determining a new cumulative mismatch metric based on each mismatch metric determined for the Y sets of data bits; 
 comparing the new cumulative mismatch metric to the threshold; and 
 completing link synchronization responsive to the new cumulative mismatch metric being less than the threshold. 
 
     
     
       11. The method of  claim 9 , further comprising decoding Reed-Solomon Forward Error Correction (RS-FEC) encoded data based on the completed link synchronization. 
     
     
       12. The method of  claim 7 , further comprising:
 performing link synchronization based on the adjustable scaling factor having a first value and mismatch metrics for a first number of sets of data bits; and 
 performing link maintenance based on the adjustable scaling factor having a second value and mismatch metrics for a second number of sets of data bits, the second value greater than the first value, and the second number of sets greater than the first number of sets. 
 
     
     
       13. A system comprising:
 a first integrated circuit (IC) having a transmitter; 
 a serial communication interface; and 
 a second IC having a receiver in communication with the transmitter via the serial communication interface, the receiver configured to:
 receive a set of data bits; 
 compare the set of data bits to a sync header pattern, wherein the comparing includes comparing each bit of the set of data bits to a respective bit of the sync header pattern to detect a corresponding bit mismatch; 
 determine a mismatch metric based on the corresponding bit mismatches and an adjustable scaling factor; and 
 execute link synchronization operations based on the mismatch metric. 
 
 
     
     
       14. The system of  claim 13 , wherein the first IC includes a baseband processor and the second IC includes a data converter. 
     
     
       15. The system of  claim 13 , wherein the first IC includes a data converter and the second IC includes a baseband processor. 
     
     
       16. The system of  claim 13 , wherein the receiver is configured to execute the link synchronization operations by:
 comparing the mismatch metric to a mismatch threshold; 
 incrementing a sync index offset responsive to the mismatch metric being greater than the mismatch threshold; and 
 repeating the receive, determine, comparing, and incrementing for new sets of data bits based on the sync index offset until a related mismatch metric is less than the mismatch threshold. 
 
     
     
       17. The system of  claim 16 , wherein the receiver includes a link layer configured to decode Reed-Solomon Forward Error Correction (RS-FEC) encoded data based on a completed link synchronization. 
     
     
       18. The system of  claim 13 , wherein the mismatch metric is a first mismatch metric, and the receiver is configured to execute the link synchronization operations by:
 repeating the receive, and determine for X sets of data bits offset by an offset, where X is an integer greater than 1; 
 determining a cumulative mismatch metric based on the first mismatch metric and each mismatch metric determined for the X sets of data bits; 
 comparing the cumulative mismatch metric to a threshold; and 
 completing link synchronization responsive to the cumulative mismatch metric being less than the threshold. 
 
     
     
       19. The system of  claim 18 , wherein the receiver is configured to execute the link synchronization operations by:
 incrementing a sync index offset responsive to the cumulative mismatch metric being greater than the threshold; 
 repeating the receive, and determine for Y new sets of data bits offset by an offset, where Y is an integer greater than 2; 
 determining a new cumulative mismatch metric based on each mismatch metric determined for the Y sets of data bits; 
 comparing the new cumulative mismatch metric to the threshold; and 
 completing link synchronization responsive to the new cumulative mismatch metric being less than the threshold. 
 
     
     
       20. The system of  claim 13 , wherein the receiver is configured to:
 perform link synchronization based on the adjustable scaling factor having a first value and mismatch metrics for a first number of sets of data bits; and 
 perform link maintenance based on the adjustable scaling factor having a second value and mismatch metrics for a second number of sets of data bits, the second value greater than the first value, and the second number of sets greater than the first number of sets.